The invention relates to photographic film and film handling equipment and more particularly relates to clamping rollers, film winding apparatus, assemblies, and methods.
A variety of spools and quills (here referred to collectively as xe2x80x9crollersxe2x80x9d) have been used to wind photographic filmstrips. A continuing problem has been attaching the filmstrip to the roller and later detaching the filmstrip. Tape has commonly been used to attach the filmstrip, but this adds additional steps and materials and presents a risk of contamination of processing materials by the adhesive unless the tape bearing segment of the film is segregated.
Another approach is to attach a narrowed end of the filmstrip, or a leader attached to the filmstrip, by insertion in a slot or other structure and then winding. The filmstrip is held in place by frictional contact with the margins of the slot and other surfaces of the roller until a turn of the filmstrip overlaps. The increased friction tightens the filmstrip, cinching the filmstrip against the roller. Other approaches use an external guide in place of the slot to hold the filmstrip in place until cinching occurs. These procedures have the general shortcoming that cinching effectiveness decreases with increased winding speed. It is thus preferable, in these procedures, to always wind slowly or to cinch slowly and then increase winding speed after cinching is achieved. Winding speed can be increased by the use of structures on the roller that help grip the end of the filmstrip. U.S. Pat. No. 4,972,649 discloses a quill having a forked end and a spring positioned between the tines of the fork to help hold the end of the filmstrip.
Another approach similar to the above-described cinching procedures is to wedge the end of the filmstrip or leader into a narrow passage and then wind the filmstrip over the roller. This wedging procedure has the shortcoming that the better the filmstrip is wedged for initial film winding, the more difficult it is to remove the filmstrip later.
Another approach is to initially hold the filmstrip in place by pulling a vacuum through the roller. The vacuum can be released after one or more turns of filmstrip have been wound and the filmstrip is cinched. This approach requires that the filmstrip has good initial contact with the roller in order to establish the vacuum.
It would thus be desirable to provide an improved spool, apparatus, camera, and method in which film or other media is gripped easily by the spool for winding, but released easily to permit unwinding of all the film or media away from the spool. It would also be desirable to provide an improved spool, apparatus, camera, and method in which the film can be released from the spool while the film or media is enclosed in a light-tight housing.
The invention is defined by the claims. The invention, in its broader aspects, provides a pinch spool having a core rotatable about a longitudinal axis. The core has a recess sector and adjoining chock sector. The chock sector has a greater radial dimension than the recess sector. A sheath is mounted coaxially over the core and is rotatable with the core about the axis. The sheath has an outer face, an inner face, and a longitudinal slot extending between the faces. The slot narrows to a throat at the inner face. The inner face includes a grip surface spaced apart from the throat. The grip surface is longitudinally aligned with the sectors. The sheath is pivotable about the axis between first and second angular orientations relative to the core. The slot is radially aligned with the chock sector at the first angular orientation. The grip surface is radially aligned with the chock sector at an intermediate angular orientation relative to the core. The intermediate angular orientation is between the first and second angular orientations. At least one annular support rim is fixed to one of the core and sheath. The support rim is spaced from the slot. The core and sheath grip a filmstrip or other media strip in a spool-media unit and method. In a completed one-time use camera a filmstrip is freely separable from the pinch spool.
It is an advantageous effect of at least some of the embodiments of the invention that an improved spool, apparatus, camera, and method in which film or other media is gripped easily by the spool for winding and can be easily released for later unwinding away from the spool, while still remaining coiled around the spool. It is also an advantageous effect of at least some of the embodiments of the invention that an improved spool, apparatus, camera, and method are provided in which the film can be released from the spool while the film or media remains coiled and enclosed in a light-tight housing such as a camera body.